Oil-switch.



E. M. HEWLETT & G. E. EVELETH. I

OIL SWITCH.

APPLICATION FILED NOV. 12, 1904.

1,093,05 1 Patented Apr. 14, 1914.

Fig/ I WA ew e Charles BEveletlz BY UNITED STATES PATENT OFFICE.

EDWARD M. HEWLETT AND CHARLES E. EVELETH, OF SCHENECTADY, YORK,

ASSIGNOBS T GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

OIL-SWITCH.

Specification of Letters Patent.

Application filed November 12, 1904. Serial N 0. 232,413.

Patented Apr. 14, 1914;

To all whom it may concern Be it known that we, EDWARD M; I-Inwcounty of Schenectady, State of New York, have invented certain new and useful Improvements in Oil- Switches, of which the following is a specification.

The pre nt invention relates to electric switches 0 the oil break type such as are employed in controlling high potentlal circuits, and has reference particularly to the construction of the oil pot or receptacle 1n which the arc is drawn, the principal object of the invention being to provide a novel oil pot construction by which the switch will be rendered more efiective in operation with a minimum increase in cost of construction.

The present invention is an improvement .upon the oil pot construction proposed 1n an application No. 232,603, filed Nov. 14, 1904, by Edward M. Hewlett, one of the joint applicants in the present case. In the Hewlett construction the oil pot is provided with an interior baflle-plate arranged to pocket the oil in the neighborhood of the arc, and having an opening through which.

one of the contacts moves. In operation, the are being drawn on one side of the baflleplate is subjected not only to pressure, but

also to the current of the escaping oil. This current is instrumental in carrylng 01f the are products from the instant the arc is formed, but by reason of the arrangement of the parts it acts in the direction of movement of the movable contact and does not reach its full destructive value until the arc is drawn through the opening of the bafiie-plate. A

The principal object of the present 1nvention is to construct an oil pot which, acting on this same principle, will utilize the pressure produced by the arc to create a current of oil which will be instrumental in extinguishing the are but to better advantage. This is preferably accomplished by arranging the parts so that the ,pressure will be confined in the neighborhood of the is brought directly in contact with the arc in its incipient stages and is therefore very effective in extinguishing it.

Our invention may be viewed in other aspects. and it also comprises other features which will be best understood by referring to the following detailed description. taken in connection with the accompanying draw ing, and the scope of the invention will be particularly pointed I out in the appended claims.

In said drawing, Figure 1 is an elevation of an oil switch having an oil pot con" structed in accordance with the present invention,-and Fig. 2 is a'sectional elevation of the oil pot drawn to an enlarged scale.

Referring in detail to the drawing, 10 designates the oil pot, which preferably consists of closed cylinderll having its interior divided into two compartments by an interior cylinder 12. The exterior cylinder is closed at its lower end and suitably supported upon an insulator 13, and at its upper end is provided with a cover 14; having an insulating guide 15 through which the movable contact rod,16 of the switch is adapted to'pass. The interior cylinder 12 is secured at its upper end to the under side of the cover 14 and is provided at its lowerend with a tubular contact 17 with which the lower end of contact rod 16 is adapted to vents 19 at the bottom of the interior cylinder, andleakage through the yielding "contact 17, the oil is permitted to rise to the same level in both cylinders after any operation of the switch. Suitable vents 20 in the cover 14 lead from the interior of the outer cylinder to atmosphere.

In the present instance a plurality of oil potsis employed for each circuit. These oil pots are arranged in pairslocated within fire-proof cells, formed by the'brick walls 22 and the fire-proof doors 23. Each pot is mounted directly upon a terminal 23 which extends down through the porcelain or glass insulator 13. This insulator as clearly illustrated is mounted upon a'suitable slab 21 of slate or other insulating material, located within the fire-proof The upper ends of the contact rods 16 are mechanically and electrically connected by meansof a yoke 27 secured to the lower end of a wooden or other insulated rod 27 which extends upward through the cap 24 of the cell structure. When the switch is in the closed position the circuit is completed between the terminals 23* through the oil pot to the'conducting yoke 27 as follows: terminal 23?, exterior cylinder 11, cover 14:, interior cyl-.

- inder 12, contact 17 and contact rod 16.

- From the above it will be apparent that in operation as the terminal 16 is quickly drawn upward the arc will be drawn under the oil in one of the compartments, viz. between the lower end of the contact 16' and the contact 17 within the interior cylinder 12. This will have the effect of compressing the oil in this cylinder and to a certain extent forcing it upward against the air cushion at the upper end of the cylinder, but .the difl'erence in pressure in the two cylinders will cause the oil in the inner cylinder to rush through the opening in the contact 17 to the exterior cylinder, the vents 2O preventing the formation of ah air cushion above the oil in the outer cylinder.

' that at the same time a certain amount of oil relatively small compared with the opening in contact 17 so that the most of the oil that escapes from the interior cylinder will pass through the opening in the contact 17. The oil under pressure in the interior'cylinder will act upon the arc to confine it to narrow opening thereby extinguishing the arc store it has been drawn to any considerable extent. The rupturing of circuits carrying large amounts of energy will produce enormous pressures within the inner cylinder. This pressure is counteracted by the structure of the inner cylinder and cover which must be sufliciently strong to withstand it.- Thus it is possible to construct the exterior cylinderof relatively light material thereby reducing the cost of roduction: It is obvious that the strain on t e inner cylinder may be relieved and the capacity of the switch increased by decreasing the quantity of oil employed thereby increasing the air cushion within the inner cylinder. In some cases it may even be desirable to operate the switch without oil and in such operation the air within the oil. pot will be actuated in substantially the same way as the oil. Upon test the case.

It will also be, apparent disclosed in application, Serial No. 4314,

filed February 17, 1900, by Edward M. Hewlett, one of the applicants in the present tive mechanisms might be employed to advantage and in fact the pneumatic mechanism herein disclosed has been practically superseded in practice-by electric actuating mechanism, but we have desired to illustrate pneumatic -means because of its simplicity. This pneumatic mechanismv is mounted on cap 24 of the cell structure of the switch and It is of course obvious that other mocomprises a cylinder 25 provided with a piston 26 having its rod connected to the upper end of the wooden rod-27*. Movement is given to the piston 26 by admlttlng .compressed air or other fluid through the supply pipes 28, 29,- 30 to either side of the plston. The supply of fluid to the cylinder is controlled by avalve 31 provided, with suitable supply and exhaust ports. It is obvious that the pipingwmay. be arranged in any desired manner and that the controlling valve 31 may be located at a point distant from the main switch in order to insure safety to the operator.

From the above it will be apparent that when air is admitted'through the pipes 28 and 30 to the. under side of the piston, it

will be .forced upward and at the same tlme the contacts 16 and 17 in each of the oil pots will be separated and the circuit broken in the manner previously described. On the other hand, if air is admitted through the pipe 29 to the-upper side of the piston, it willbe forced downward and the circuit thereby closed. In order to retain the switch in open position, that is with its piston up,

without maintaining air pressure in the lower; end of the cylinder, we provide a latch 31 which engages a collar 32 at the upper end of the rod 27. This latch is normally. thrown into engagement with the V collar by gravity. In order to release the latch a releasing pin 33 is employed. This pin at its lower end engages the latch 31* and at its upper end is secured to a diaphragm located in a chamber 34 and in communication at its upper side to the V piping 35 with the upper end of the cylinder 25. With this organization whenair is ad mitted' to the upper end of the cylinder it will also be admitted to the upper side of the diaphragm and will force the pin 33 downward against the latch 31 thereby respirit and scope of the present invention;

We therefore do not wish to be'limited to .the specific matter shown and described but aim to cover by the terms of the appended claims all equivalent constructions.

What we claim as new, and desire' to secure by Letters Patent of the United States, 7 i

1. An electric switch com rising separable contacts, one at least of which is provided with an opening, a chamber for the contacts, and immovable means located therein for confining the pressure produced by the are so that it can escape only through said contact opening thereby extinguishing the arc;

2. An electric switch comprising ,an oil pot, separable cont-acts therein, one of'said contacts being tubular, and immovable means within the pot for restraining the displacement of the oil by the arc and permitting escapement only through the tubular contact and returning the oil to its normal location when the pressure due to the arc subsides.

3. An electric switch comprising a chamber, separable contacts arranged to break therein, an opening through one of saidcontacts, said opening communicating between difierent portions of said chamber and arranged to direct the pressure produced by the arc against the are so as to extinguish it. 4. An electricswitch comprising an oil spot, separable contacts arranged to break therein under-oil, an opening through one of I said contacts, said open ng communicatin tween said compartments comprising saidbetween difierent portions of said t an arranged to conduct the oil displace by the are against the are so as to'extinguish 1t.

5. An electric switch comprising atwo compartment chamber, separable contacts arranged to break-in one of said compartments, an opening through one of said contacts, and communicating means between said compartments comprising said openmg arranged to direct the pressure produced by the arc against the are so as to extinguish it.

6. An electric switch comprising a two compartment chamber, separable contacts arranged to break in one of said compartments under oil, an opening through one of said contacts, and commumcatiiig means beopening arranged to direct the oil displaced by the arc gasw against the are so as to ex-, tinguish it. I

- 7. An electric switch comprising a two compartment oil pot, a tubular contact forming a commumcating passage between forcibly close the said compartments, and a coiiper'ating contact arranged to break therewith in one of said compartments. c

8. An electric switch comprising a. two compartment oil pot, each of which compart-ments is partially filled withoil, separable cont-acts arranged to break under oil in one of said compartments, and means for conducting the oil put under pressure by the arc gases against the are so as to extinguish it. v

.9. An electric switch comprising a two compartment oil pot, eachof which compartments is partially filled with oil, separable contacts arranged to break under oil in one of said compartments, and an oil conducting passage between said compartments arranged to conduct the oil displaced by the arc gases against the are so as to extinguish it.

10. An electric switch comprising a'twocompartment oil chamber having one 'compartment located interiorly of the other, separable'contacts arranged to break in one of said compartments, and a communicating passage between said compartments controlled by one of said contacts.

11. An electric-switch compr sing a twocompartment oil chamber having one compartment located interiorly of the other, separable contacts arranged to break in the interior compartment and a communicating passage between said compartments controlled by said contacts.

- 12. An electric'switch comprising a two compartment oil chamber having one compartment located interiorly of the other, separable contacts arranged to break in one of said compartments, and means for utiliz-' ing the pressure produced by the arc to extinguish the are 13. An electric switch comprising a two compartment oil chamber having one com=-- partment located interiorl vof the other,

. I separable contacts arrange to break in one of said compartments under oil, andinean's for utilizing the oil put under pressure by the arc gases to extinguish the arc.

, 14. An electric switch comprisinga two compartment oil chamber having onev compartment located interiorly of the other, separable contacts arranged to break in the interior compartment underoil, and means for utilizing. the oil'put under pressure by the arc gases in extinguishing the are.

15. An electric switch comprising an oil ot consisting of two cups located one with-' in the other, and se arable contacts arranged to break in the inner cup, one of said, contacts being carried by the inner cup and" having an opening therethrou h constitut ing a communicatlng passage tween said on s.

6. An electric switch compris' an oil pot consisting of two cups. of ifierent depths located-one within the other, a cover I- other compartment and against the arc to common to said cups, a tubular contact in the bottom of the inner cup providing a csel containing insulating fluid, relatively communicating passage betweensaid cups, and a cooperating movable contact extending into the inner cup through said cover.

17. In an electric switch, the combination of cotiperatin contacts, one of which has an opening t erethrough, a chamber surrounding said contacts, and means for causing an insulating medium under pressure to force the arc gases through said'opening. 18. An electric switch comprising a two compartment chamber with a communicating passage between said compartments, and separable contacts mounted to separate in one of said compartments under oil and draw an are adjacent said passage and in the path of oil flowing out of said compartment through said passage, whereby the oil put under pressure by the arc is directed against the arc to extinguish it. Y

19. An electric switch comprising an oil pot having two compartments, one inside the other, with a passage between them, one of said compartments containing bil, and separable contacts mounted to draw an arc in the compartment containing oil and adjacent said passage, whereby the oil put .under pressure in said compartment by the arc is directed through the passage into the extinguish it.

20. An electric switch comprising a vesmovable cooperating contacts mounted to separate in said vessel, a vent adjacent the arcing surface of one of said contacts, and immovable means mounted within said vessel to confine said -fluid under pressure and to direct it through said vent and over the arcing surface of one of said contacts in a direction opposite to the direction of movement of the other contact during the separa tion of said contacts.

the arcing surface of said stationary contact I during'the separation of said contacts.

In witness whereof we have hereunto set our hands this 3rd day of November, 1904.

. EDWARD M. HEWLETT.

. CHARLES E. EVELETH.

Witnesses:

BENJAMINB. HULL, HELEN ORFORD. 

